JP2848247B2 - Toroidal type continuously variable transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toroidal-type continuously variable transmission, and more particularly to a toroidal-type continuously variable transmission by devising a combination structure of a pivot shaft holding a power roller and a roller supporting member supporting the pivot shaft at one end thereof. An attempt is made to simplify the structure without lowering the strength.

[0002]

2. Description of the Related Art Generally, a toroidal type continuously variable transmission is provided with an input / output disk opposed to a main shaft (input shaft), a power roller for transferring power by frictional engagement between the input / output disks, and a power roller. A roller support member that supports a pivot shaft holding the power roller at one end; a hydraulic cylinder that moves the roller support member up and down to tilt the power roller in a frictionally engaged state; Normally, it is constituted by a combination with a shift control unit that changes the degree of inclination of the roller to perform a continuously variable shift. As a prior document relating to this point, for example, Japanese Patent Application Laid-Open No. 3-89066 is disclosed. Referenced.

In the conventional continuously variable transmission disclosed in the above-mentioned publication, as shown in FIG.
The bearings 4 and 25 are incorporated into the roller supporting members 28 and 29 via needle bearings 26 and 27. However, from the viewpoint of simplifying the structure at this portion and improving the workability when assembling the transmission, the bearings are bushing. Although it is desired to use such a type of bearing, there have been various problems as described below, and it has been difficult to realize such a problem.

That is, in this type of continuously variable transmission, the roller supporting members 28 and 29 receive the thrust load of the power rollers 30 and 31 and warp, so that the pivot shafts 24 and 25 rotate.
At the rear end (point b), the bearings 26 and 27 interposed between the roller and the roller support members 28 and 29 exert a force to expand vertically (causing deformation to become a vertically long ellipse). Conversely, at the tip (point a), a force is exerted to expand right and left (causing deformation to become a horizontally long ellipse). At the front and rear ends, the surface pressure locally increases, and when the strength is relatively weak, such as a bush, the rotation of the pivot shaft is hindered, and the power roller smoothly tilts when performing continuously variable transmission. There was a disadvantage that it could not be done.

[0005] In order to solve the above-mentioned problem that is a concern when a bush is applied, it is conceivable to reduce the length of the bush. However, since the load applied to the entire bush increases, the life of the bush becomes extremely short. Be shorter.

An object of the present invention is to propose a continuously variable transmission that can simplify the structure without hindering the tilting of the power roller.

That is, the present invention relates to an input / output disk opposed to a main shaft, a power roller for transferring power by frictional engagement between the input / output disk, and a pivot shaft for rotatably holding the power roller. A roller support member for supporting at one end thereof, a hydraulic cylinder for tilting the power roller in a frictionally engaged state by moving the roller support member up and down, and changing the degree of tilt of the power roller by operating the hydraulic cylinder In the toroidal-type continuously variable transmission including a shift control unit that performs a continuously variable transmission, a bush that rotatably holds the pivot shaft is disposed between the roller support member and the pivot shaft,
The pivot shaft is provided with a lightening hole extending along an area where the bush is disposed, and is a toroidal-type continuously variable transmission. It is desirable to have a gap between the area and the roller supporting member that holds the bush fixedly, and it is preferable that the lightening hole and the gap overlap each other along the axial direction of the pivot shaft. .

[0008]

When the rigidity of the bearing portion is reduced by forming a lightening hole extending along the area where the bush is arranged on the pivot shaft, the thrust load of the power roller is applied to the roller support member and the pivot shaft is bent. Since the (area where the lightening hole exists) is also deformed, a local increase in the surface pressure at both ends of the bush is suppressed (the invention according to claim 1).

In addition to the formation of such a lightening hole,
By forming a gap between the end area of the bush on the power roller side and the roller supporting member for fixing and holding the bush, the surface pressure at both ends of the bush to which a large force is applied can be effectively reduced. Invention concerning 2).

Further, by overlapping the gap with the lightening hole formed in the pivot shaft, the rigidity of the bearing portion along the longitudinal direction of the bush can be reduced substantially uniformly over its entire length, and the local portion of the bush can be reduced. A large increase in surface pressure is suppressed (the invention according to claim 3).

As described above, according to the present invention, the pivot shaft is provided with a lightening hole in order to reduce the rigidity of the bearing portion in the portion where the pivot shaft and the roller support member are combined, or in addition to this, the bush and the bush are provided. Although a gap is formed between the roller support member and the gap, it is desirable to provide such a lightening hole and a gap as long as the structural strength of the transmission is not reduced.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings.

FIGS. 1 and 2 show the configuration of a toroidal type continuously variable transmission according to the present invention. In the drawing, reference numerals 1 and 2 denote input / output disks arranged on the main shaft m, reference numerals 3 and 4 denote power rollers for transferring power by frictional engagement between the input disks 1 and 2, and reference numerals 5 and 6 denote power rollers 3, 4. Is rotatably held, and the pivot shafts 5 and 6 are provided with lightening holes 5a and 6a, respectively.

Reference numerals 7 and 8 denote roller support members. The roller support members 7 and 8 rotatably support the pivot shafts 5 and 6 at one ends thereof via bushings 9 and 10, respectively. .

Reference numeral 11 denotes a hydraulic cylinder having a built-in piston P, and reference numeral 12 denotes a transmission control unit disposed below the hydraulic cylinder 11. The transmission control unit 12 includes a valve body, a spool, a rack shaft, a cam and the like. The shift control unit 12 moves the piston P of the hydraulic cylinder 11 and the roller support members 7 and 8 up and down, and changes the degree of tilt of the power rollers 3 and 4 connected to the piston P to change the continuously variable speed. Let it do.

FIG. 3 is an enlarged view of a main part of the continuously variable transmission shown in FIGS. In this example, the lightening holes are also provided in the portions of the pivot shafts 5 and 6 for holding the power rollers 3 and 4, but this is provided from the viewpoint of reducing the weight of the members.

FIGS. 4 to 7 show another example of the toroidal-type continuously variable transmission according to the present invention with respect to the essential parts.

FIG. 4 shows a pivot shaft formed between the roller support member 7 (8) and a lightening hole formed in the bush 9 (same as the bush 10), and the diameter of the end region on the power roller side is reduced. 5 (6) has a structure in which gaps g are formed at the same interval along the axial direction, and FIG.
Tapered to the end region of the power roller side of the bush 9 (10), it is of the structure forming a gap g ₁ gradually larger wedge toward the power roller side, further, 6, 7 By processing the roller supporting member 7 (8), the gaps g, g ₁ as shown in FIG. 4 or FIG.
In any of the examples, the rigidity of the bearing portion is reduced.
(10) will not be extremely deformed by the influence of the thrust load of the power rollers 3 and 4.

In the structure shown in FIGS. 6 and 7, the roller supporting members 7 and 8 need to be processed.
It is particularly advantageous to apply the structure as shown in FIGS. 4 and 5 in terms of simplifying the manufacturing process.

L in FIGS. 4 to 7 denotes a lightening hole 5a.
(6a) and the gap g, which shows the overlap length of g _1. In the present invention, the intended purpose can be sufficiently achieved by providing the lightening hole. However, only the lightening hole uniformly reduces the rigidity of the bearing portion over its entire length (the area where the bush is arranged). Since there is a concern that the hole cannot be formed, it is desirable to make the lightening hole and the gap overlap as shown in the figure. The overlap length may be adjusted within a range where the strength of the member is not reduced.

Another configuration of the continuously variable transmission shown in FIGS. 1 and 2 will be described in detail below.

The contact state of the power rollers 3, 4 arranged between the input disk 1 and the output disk 2 is changed by the hydraulic cylinder 11, whereby the rotation speed ratio of each disk changes.

The input disk 1 is rotatably held on the outer periphery of a main shaft (input shaft) m via a ball spline. The main shaft m is connected to a forward / reverse switching mechanism and a torque converter (not shown), and passes therethrough. The engine torque is input.

A cam flange 1 is provided on the back of the input disk 1.
3, and a cam roller 14 is arranged between the cam flange 13 and the input disk 1. Cam roller 1
Numeral 4 generates a force for pushing the input disk 1 to the output disk 2 when the input disk 1 and the cam flange 13 are relatively rotated.

The output disk 2 is rotatably held on the main shaft m via a needle bearing.
A key 18 is integrally attached to an output gear 17 rotatably supported on a casing 16 via a key 5.

The roller supporting members 7 and 8 are provided on the upper and lower rotating shaft portions 7a and 7b and 8a and 8b, respectively.
It is rotatably supported at 9 and 20, and is supported so that it can move up and down.

The spherical bearings 19 and 20 are fixedly held via link 22 to link posts 21 provided on the casing.

The roller support members 7, 8 are provided with rotary shaft portions 7a,
7b, 8a, 8b and concentric with the rotary shaft.
Rollable extension shaft P_LHaving. This extension shaft P_LOutside
A piston P is provided around the circumference, and an extension shaft (pist
Having the function of a rod) P _LPiston P and cylinder
Body C₁, C_TwoThe hydraulic cylinder 11 is constituted by
You.

[0029] and below the piston P moves up and down together with the extension shaft portion P _L serving as a piston rod of the piston P by supplying hydraulic oil here have oil chamber is formed.

The cam 23 provided at the lower end of the extension shaft portion P _L of the hydraulic cylinder 11 and the cam link 12a provided on one end of the shift control unit 12 is in engagement, the input and output disks by such cam 23 The transmission ratio is fed back to the transmission control unit.

When the piston P is moved upward or downward by controlling the hydraulic pressure in the hydraulic cylinder 11, the power rollers 3, 4
Since the direction of the force (normal force) acting on the power rollers 3 is changed, the power rollers 3 and 4 are frictionally engaged with the input and output disks 1 and 2 around the rotary shafts 7a, 7b, 8a and 8b. The gear ratio changes according to the degree of tilt.

[0032]

According to the present invention, the bush for rotatably holding the pivot shaft is not greatly deformed even when the thrust load of the power roller is received, so that the roller supporting member in the toroidal type continuously variable transmission can be used. And the pivot shaft can be simplified.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a configuration of a transmission according to the present invention.

FIG. 2 is a diagram showing a II section of FIG. 1;

FIG. 3 is a view showing a cross section of a main part of FIG. 1;

FIG. 4 is a diagram showing a cross section of a main part of the continuously variable transmission according to the present invention.

FIG. 5 is a diagram showing a cross section of a main part of the continuously variable transmission according to the present invention.

FIG. 6 is a diagram showing a cross section of a main part of the continuously variable transmission according to the present invention.

FIG. 7 is a diagram showing a cross section of a main part of the continuously variable transmission according to the present invention.

FIG. 8 is a diagram showing a configuration of a conventional continuously variable transmission.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Input disk 2 Output disk 3 Power roller 4 Power roller 5 Pivot shaft 6 Pivot shaft 7 Roller support member 8 Roller support member 9 Bush 10 Bush 11 Hydraulic cylinder 12 Shift control unit 13 Cam flange 14 Cam roller 15 Ball bearing 16 Casing 17 Gear 18 Key 19 Spherical bearing 20 Spherical bearing 21 Link post 22 Link 23 Cam 24 Pivot shaft 25 Pivot shaft 26 Needle bearing 27 Needle bearing 28 Roller support member 29 Roller support member 30 Power roller 31 Power roller m Main shaft g Clearance g ₁ Clearance L Overlap pass P _L extending shaft portion C ₁ cylinder body C ₂ cylinder body

Claims (3)

(57) [Claims] An input / output disk opposed to a main shaft, a power roller for transferring power by frictional engagement between the input / output disks, and a pivot shaft rotatably holding the power roller at one end. A roller support member for supporting, a hydraulic cylinder for tilting the power roller in a frictionally engaged state by moving the roller support member up and down,
In a toroidal-type continuously variable transmission having a shift control unit that operates the hydraulic cylinder to change the degree of tilt of a power roller to perform a continuously variable transmission, the pivot is disposed between the roller support member and a pivot shaft. A toroidal-type continuously variable transmission, further comprising a bush that rotatably holds a shaft, wherein the pivot shaft includes a lightening hole extending along a region where the bush is arranged. 2. The toroidal-type continuously variable transmission according to claim 1, wherein a gap is provided between an end area of the bush on the power roller side and a roller supporting member for fixedly holding the bush. 3. The toroidal-type continuously variable transmission according to claim 2, wherein the lightening hole and the gap overlap each other along the axial direction of the pivot shaft.